Experimental Medications: Monoclonal Antibodies

Like Ocrevus, Rituxan, and ofatumumab, ublituximab targets the CD20 molecule to deplete B cells. Its developer, TG Therapeutics, is evaluating the monoclonal antibody for use in treating both hematological malignancies and relapsing forms of MS (RMS). One area of inquiry in MS is whether the activity of ublituximab will enable it to be administered in lower doses and shorter infusion times than currently available anti-CD20 agents.58

Findings from a Phase II multi-center, placebo-controlled study suggest that ublituximab reduces MS disease activity, suppresses relapses, and can be safely infused in approximately one hour. Fortyeight individuals with RMS received an initial infusion of ublituximab, subsequent infusions 15 days and 24 weeks later, and then were followed for 48 weeks. Infusion times ranged between one and four hours.

Median depletion of B cells exceeded 99 percent at Week 4, and that level of depletion was maintained at Weeks 24 and 48. No enhancing lesions were seen at Weeks 24 and 48, and T2-lesion volume was decreased by 10.6 percent at Week 48, compared with baseline. Also, none of the patients who could be evaluated showed sustained disability progression. Mild to moderate infusion reactions were reported, but the incidence did not increase with faster infusion.58, 58

Two parallel, placebo-controlled, Phase III trials of ublituximab are also in progress. The global, multicenter ULTIMATE I and ULTIMATE 2 studies are comparing ublituximab with teriflunomide in people with RMS. The primary endpoint for both studies is annualized relapse rate after 96 weeks of treatment.60